Reporting on natural events under the AQ Directive

Transcription

1 Reporting on natural events under the AQ Directive Review of years 2008 and 2009 M. Viana, J. Pey, F. de Leeuw, X. Querol, A. Alastuey, M. dall Osto, T. Moreno

2 Legislative background Directive 2008/50/EC provides Member States with the possibility to subtract the contribution of natural sources under certain conditions before comparing the ambient air pollutant concentrations to the limit values. Which conditions? 1. contributions must not be caused by direct or indirect human activities; 2. quantification of the natural contribution must be sufficiently precise; 3. quantification of the natural contribution must be consistent with the averaging period of the limit value; 4. quantification of the natural sources must be spatially attributed; 5. the contributions must be demonstrated based on systematic process; 6. quantification of the natural sources must be demonstrated for each pollutant separately.

3 Aims To critically review the reporting of exceedances due to natural causes reported by Member States: years 2008 and 2009 PM 10 SO 2 : not reported in 2008 or 2009 Reporting of natural exceedances of the PM 10 daily and annual limit values

4 Natural sources Which natural sources? Commission Staff Working Paper 6771/11 (Feb. 2011) Commission Decision 2004/461/EC (questionnaire, Tables 2 and 5) Contributions eligible for subtraction: Transport of natural particles from dry regions Sea spray Volcanic eruptions & seismic activities Wild-land fires Contributions not eligible for subtraction: Primary biological aerosol particles Secondary organic biogenic aerosols Mineral dust re-suspension

5 PM annual 10 limit value 7 Member States in 2008 Mediterranean basin (CY, ES, FR, GR, IT) Western EU (GB, PT) 4 Member States in 2009 Mediterranean basin (CY, ES, FR, GR) - Low impact of natural souces on annual levels? - Lack of specific tools for the annual scale?

6 PM daily 10 limit value 10 Member States in 2008 Mediterranean basin (CY, ES, FR, GR, IT, MT) Central EU (AT, DE) Western EU (GB, PT) 8 Member States in 2009 Mediterranean basin (CY, ES, FR, GR, IT) but not in certain MS (e.g., MT) Western EU (GB, PT) Northern EU (LV)

7 Causes for natural exceedance Stations reporting natural events of each category Stations reporting natural events of each category 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% AT CY DE ES FR GB GR GR GR IT LV MT PT AT CY DE ES FR GB GR GR GR IT LV MT PT Unknown Sea salt Wild-land fire Natural sources African dust

8 Causes for natural exceedance 2008 African dust Wild-land fires Natural source Sea salt

9 Causes for natural exceedance 2009 African dust Natural source Wild-land fires Sea salt Unknown

10 Causes for natural exceedance Dominant natural cause: African dust, reported by 70% and 50% of the MSs reporting natural events in 2008 and 2009 Exc. due to the general term natural source were reported by 30% and 50% of the MSs in 2008 and 2009 The analysis of the methodologies suggests that natural source referred to African dust in all cases, and in addition to sea salt in GB Other causes reported by single MSs were: wild-land fires and an unspecified cause by GR, and embruns marins by FR.

11 PM daily 10 limit value % stations reporting natural exceedances Mediterranean + LV: >30% (CY, ES, GR and MT) Rest: <10% General decrease from 2008 to 2009 (excl. GB, IT) 100% 90% 80% year 2008 year % % of stations 60% 50% 40% 30% 20% 10% 0% AT CY DE ES FR GB GR IT LV MT PT

12 Nr. of exceedances of the DLV Depends on meteorology: rules transport mechanisms of natural events but also anthropogenic pollution scenarios Mediterranean Member States reported the highest numbers: natural exc./year (also with broadest ranges) Lower numbers of natural exc. were reported by PT (6-20 in 2008) Maximum reported by FR (128 exc./year in 2009): isle of La Réunion Nr. of natural exceedances/station Number 100 of natural exc./station was relatively similar among Mediterranean MSs, with an increasing trend from West to East (Moulin et al., 1989; Querol et al., 2009) AT CY DE ES FR GB GR IT LV MT PT

13 Effect of correction by natural causes Number of stations Stations reporting natural exceedances of the DLV Stations reporting exceedances of the DLV after subtraction of natural contribution PM 10 daily limit value Number of stations Stations reporting natural exceedances of the DLV Stations reporting exceedances of the DLV after subtraction of natural contribution % reduction of stations surpassing 5035 exc./year after correction: 100% in CY and MT % in GB, GR and PT % in ES 20 25% in IT Number of stations AT CY DE ES FR GB GR IT LV MT PT 2008 PM 10 annual limit value Stations reporting natural exceedances of the ALV Stations reporting exceedances of the ALV after subtraction of natural contribution CY ES FR 16th GB EIONET GR Workshop PT on Air Quality Assessment CY ES and Management FR GB GR PT Number of stations AT CY DE ES FR GB GR IT LV MT PT 2009 % reduction of stations surpassing 1040 µg/m 3 after correction: 100% in CY, GB and PT 8 50% in ES 6 33% in FR 4 25% in GR Stations reporting natural exceedances of the ALV Stations reporting exceedances of the ALV after subtraction of natural contribution

14 Assessment of methodologies Language inhomogeneity: national languages or English were used Not all methodologies were reported (CY, IT, LV missing) Certain methodologies are not included in EC Guidance document 6771/11. However, reporting was done for The assessment of methodologies allowed to understand the general code natural events : sea salt in GB, African dust in MT. Not for LV, where the natural causes reported are still unspecified

15 Assessment of methodologies * Gibraltar Cause Language Quantitative (ALV) Qualitative (DLV) Eligible method AT African dust EN + DE CY African dust EN DE African dust EN DE African dust DE ES African dust ES FR African dust FR FR Sea salt FR GB Sea salt EN GB* African dust EN GR African dust GR GR Wild-land fires GR IT African dust - LV?? - MT African dust EN MT Sea salt EN PT African dust PT

16 Conclusions The natural sources eligible for subtraction should be homogenised: documents 2004/461/EC and 6771/11 A natural events code should be created for sea salt (2004/461/EC, Tabl.5) African dust was the dominant natural cause: 70% and 50% of the MSs reporting natural events in 2008 and 2009 Reporting of African dust events seems correct, following spatial and temporal trends described in scientific literature Effect of correction for natural events: % reduction of exceedances of the PM 10 daily limit value % reduction of exceedances of the PM 10 annual limit value Methodologies: Most methods applied were only qualitative Most MS did not follow the recommendations in the EU Guidance document 6771/2011, and only about 30% applied comparable methods

17 Thank you for your attention!